The present invention relates to heatpipes, and more particularly, relates to three-way heat pipes with a generally Y-configuration in which the leg functions as both a condenser and evaporator alternately, one arm functions as an evaporator and the third arm as a condenser. The invention relates further to a system employing three-way heat pipe for collecting, storing and utilizing thermal energy.
The increased cost of fossil fuels has directed much attention to various systems for collection and storage of thermal energy, both passive and active and combinations thereof. Typically, solar collectors have been used to collect heat energy which is then conveyed, usually by a flow loop or heat pipe, to a heat storage means for later use. Also, structural support assemblies for use in the Artic and Sub-Artic regions, which are characterized by a permafrost layer below the tundra, have been used to maintain the permafrost layer in the frozen condition so as to avoid freeze-thaw cycles and the associated heaving of the soil. These structures, sold under the trademark CRYO-ANCHOR, by the assignee of this patent, have been used extensively on the Alaskan pipeline and are nothing more than a heatpipe which conveys the cold in the air into the ground.
The ground is a very popular spot for storage of collected thermal energy as the Earth has an extremely large heat capacity as well as extremely low thermal conductivity. The latter is important since the storage is generally unbounded by insulation in at least two directions. However, in the case of the cold storage water or ice may be a more efficient storage means.
U.S. Pat. No. 4,138,995 to Yuan, teaches a pumped heatpipe for solar collection and storage along with a second pumped fluid loop for heat distribution. U.S. Pat. No. 4,240,268, to the same inventor, teaches a pumped heatpipe to freeze ice during the winter, plus a second pumped fluid loop for space cooling of buildings during the summer.
Both of these systems are complicated by the requirement for a separate pumped fluid loop to distribute the stored heat or cold which adds cost and increases the active elements subject to breakdown.
It is an important object of this invention to eliminate the second pumped fluid loop for heating or cooling distribution by use of a novel heat pipe arrangement.
It is a further object of this invention to isolate any portion of the heat transfer device from transferring unwanted heat while the conditioned space is demanding cold or vice versa.